# HK80UTM_TO_HK80GEO: Convert the HK80UTM coordinates to HK80GEO coordinates In HK80: Conversion Tools for HK80 Geographical Coordinate System

## Description

Convert the HK80UTM coordinates to HK80GEO coordinates

## Usage

 `1` ```HK80UTM_TO_HK80GEO(N, E, zone = c(49, 50)) ```

## Arguments

 `N` Numeric, Northern coordinate in meters. `E` Numeric, Eastern coordinate in meters. `zone` zone, UTM zone, either 49 or 50 for Hong Kong.

## Details

This function uses equation 3, 4, 5 in the explanatory notes to convert the HK80UTM coordinates into HK80GEO coordinates (latitude and longitude) in decimal degrees. Mode details could be found at: Page C9 and C10 on the explanatory notes.

## Value

 `latitude ` latitude in decimal degrees `longitude` longitude in decimal degrees

## Note

The coordinates should be within the range of Hong Kong. Providing coordinates outside Hong Kong will lead to wrong results.

Jinlong Zhang

## References

Survey & Mapping Office Lands Department, Hong Kong Government (1995). Explanatory Notes on Geodetic Datums in Hong Kong, available at: http://www.geodetic.gov.hk/smo/gsi/data/pdf/explanatorynotes.pdf

`HK80GEO_TO_HK80UTM`

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```options(digits = 15) HK80UTM_TO_HK80GEO(2483775, 208930, zone = 50) #### \$latitude #### [1] 22.435188997523 #### #### \$longitude #### [1] 114.172349350774 ##### Answer from the explanatory note: ### 22 + 26/60 + 06.89/3600 = 22.43524722 ### 114 + 10/60 + 20.39/3600 = 114.1723306 ```

### Example output

```         latitude        longitude
1 22.435188997523 114.172349350774
```

HK80 documentation built on May 2, 2019, 2:10 a.m.